Soft or amorphous polymers are difficult to pelletize, convey, and further finish because the pellets tend to agglomerate or stick together. Amorphous polymers having low viscosity or high MFR of greater than 2 g/10 min (230° C., 2.16 kg) are especially prone to this problem. To counter act this problem, the polymer has been dusted with fine powder of, for example, low density polyethylene or ethylene vinyl acetate (EVA). The required dust level, however, detrimentally affects further processing, such as packing the resin in bales. Furthermore, applications requiring such soft or amorphous polymers, such as viscosity index improvers, can only tolerate a low level of dust before solubility problems arise in the oil.
Other attempts to counter act the problem of pellet agglomerates have used semi crystalline polymers, which do not tend to form agglomerates, to produce blends which remain free flowing. This, however, will lead to changes in the final product and is acceptable only in a limited number of applications. In the case of viscosity index improvers, for example, these added semicrystalline polymers have the tendency to interact with wax in the final oil formulation and are thus unacceptable.
Yet other attempts to counter act the problem of pellet agglomerates have involved refrigeration of the conveying equipment. This however, can, lead to unacceptably high water concentrations in the final polymer.
There is a need, therefore, for a new process and system to prevent pellet agglomeration that does not require unacceptably high dust levels, refrigeration of the conveying lines or the blending of other polymer components.